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000
FXUS61 KPBZ 210106
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
906 PM EDT Tue Jun 20 2017

.SYNOPSIS...
After low chances of rain Wednesday and Thursday, a cold front
will bring widespread rain to the region on Friday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
The late eve update featured further, albeit minor, adjustments
to overnight precip probs based on the latest RAP, HRRR/consensus-
short and upstream radar trends. A shortwave/weak cold-reinforcing
front is timed to complete passage across the Great Lakes and
encroach on the immediate area later tonight.

Although current radar coverage over the Lakes is widespread,
the vorticity center is expected to rotate into the eastern
flank of the parent low just east of the Hudson Bay, thus
resulting in decreased downstream coverage as upper support
weakens.

At any rate, slight to chance POPs for showers were maintained
but with quicker onset time. These were spread southward toward
the I 70 corridor on Wednesday, with diminishment in the wake
of the disturbance late in the day.
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&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
The unsettled pattern continues into Thursday with a shortwave
moving across the area. Again, stuck with low chance pops,
primarily across northern counties. The most active weather
period for the week still appears to occur Friday into Friday
night. Models are in good agreement that another cold front will
enter the region from the west. At the same time, Tropical Storm
Cindy will continue its path from the Gulf of Mexico into the
Mississippi Valley. Still too early to be specific with the
interaction of the moisture from the tropical storm with the
front, but so far it appears that the bulk of the rainfall will
remain south of the forecast area with the front shunting the
Cindy remnants to the east. Thursday should be the warmest day
of the 7 day forecast, with temperatures about five degrees
cooler with the arrival of the front.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
The chance of showers will linger south and east of Pittsburgh
Saturday along the back side of the front, and an additional
shortwave could spark showers on Sunday. High pressure should
build in for Monday and Tuesday, resulting in quiet weather.
Temperatures will remain below normal through the extended
forecast.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
General VFR is expected to be marred only be scattered, high
based showers later tonight and Wednesday as a shortwave trough
traverses the region. Sfc wind will back from west to south
with the approach of that disturbance, then veer to the west
with passage on Wednesday afternoon.

.OUTLOOK...
Widespread restrictions are likely Friday with the encroachment
of a cold front.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...None.
OH...None.
PA...None.
WV...None.

&&

$$
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